Process of manufacturing artificial silk and other products from nitrocellulose



Patented has, 1923.

PATENT OFFICE.

EMILE BINDSCHEDLER, OF PHILADELPHIA, PENNSYLVANIA, AND GEORGE J'UER, OFHOPEWELL, VIRGINIA, ASSIGNORS TO TUBIZE ARTIFICIAL SILK COMPANY OFAMERICA, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

' PROCESS OF MANUFACTURING ARTIFICIAL SILK AND OTHER PRODUCTS FROMNITROCELLULOSE.

No Drawing.

To all whom it may-concern:

Be it known that we, EMILE BINnsonnn- LER, a citizen of the Republic ofSwitzerland, and resident of Philadelphia, in the county ofPhiladelphia, in the State of Pennsylvania, and GEORGE JUER, recently asubject of the former AustroHungarian Empire, and now a resident ofHopewell, in the county of Prince George, in the State of Virginia, haveinvented certain new and useful Improvements in Processes ofManufacturing Artificial Silk and Other Products from Nitrocellulose, ofwhich the following is a true and exact description. Our inventionrelates to the manufacture of articles from nitrocellulose andparticularly to the production of artificial silk. Heretofore it hasbeen known that acetone and its homologues are solvents ofnitrocellulose and that its or their use as such would be advantageousfrom the point of view of the comparatively easy and large percentage oftheir recovery as compared with other solvents the large losses of whichmore than offset their relative cheapness. It has been found, however,that acetone as heretofore attempted to be used, resulted in acloudiness or opacity in the finished product made from the acetonecollodion and, particularly, it is found that artificial silk so made isfriable and without lustre.

The object of our invention is to provide a method of using acetone as asolvent for nitrocellulose and for recovering the nitrocellulose fromsolution after manufacture which will produce a lustrous and strongfilament or other product and we accomplish this by dissolvingnitrocellulose in a solvent consisting in whole or in part of to acetoneor its homologues by imparting to the acetone collodion thus producedthe de sired form in the case of artificial silk, forming it into a finefilament by forcing it through spinnarettes and by extracting the 4.5solvent from the formed product by ll1l mersing said product in a liquidor solution which is mixable with acetone and in which nitrocellulose isinsoluble. This extraction of the solvents can be effected by '50immersing the spools or bobbins on which the fibres are wound in a bathof such a liquid or by providing a coagulating bath through which thefibres pass.

Application filed November 19, 1920. Serial No. 425,049.

By preference we first dehydrate the nitrocellulose before dissolving itwhich can be well effected by treating it with ethyl alcohol which neednot be extracted before the acetone solvent is applied to thenitrocellulose and by preference also we use dry acetone as a solvent asdescribed in our copendlng application filed November 19, 1920, SerialNo. 425,048, which is intended to cover the method involving thedehydration of the nitrocellulose and the use of dry acetone as asolvent. Our present invent1on having to do with the particular methodof'extracting the solvent from the filamentor other product made fromthe acetone collodion which involves the use of the li uid mixable withacetone and with out e ect upon the nitrocellulose, irrespective ofwhether the preferred method of our sald co-pending application is usedor not.

Liquids, well adapted for the removal of the acetone are organic liquidssuch as benzene or its homologues, petroleum, or fractions of it;-certa1n acids such as diluted sulphuric acid ;-and solutions of acidsalts or neutral salts, for instance, a concentrated solution of calciumchloride. Such solutions mix readily with the acetone but are entirelywithout effect upon the nitrocellulose and from all such liquids theacetone can be readily recovered for re-use by heating the liquid'anddriving off the acetone. It85 will, of course, be obvious that in placeof using acetone any of the well known homologues of acetone can beused, and we would state also that instead of using acetone or itshomologues alone or in admixture with each other, each of them may bemixed with other solvents of nitrocellulose such, for instance, asethylalcohol.

Having now described our invention, what we claim as new and desire tosecure by Letters Patent, is:

1. The method of manufacturing clear unclouded products fromnitrocellulose which consists in dissolving the nitrocellulose in asolvent made up in whole or in part of acetone or its homologues,imparting to the acetone collodion thus formed the desired form andextracting the solvent by immersing the formed product in a liquid whichis mixable with acetone and in which nitrocellulose is insoluble.

2. The method of manufacturing artificial silk filaments fromnitrocellulose which consists in dissolving the nitrocellulose in asolvent made up in Whole or in part of acetone or its homologues.forming the acetone collodion thus obtained into artificial silkfilaments by forcing it through a spinnarette and extracting the solventfrom the filaments by immersing them in a liquid which is mixable withacetone and in which nitrocellulose is insoluble.

3. The method of manufacturing artificial silk filaments fromnitrocellulose which consists in dehydrating nitrocellulose hydrate,dissolving it in a solution made up in whole or in part of dry acetoneor its homologues, forming the acetone collodion into filaments byforcing it through spinnarettes and extracting the solvent from thefilaments by immersing them in a liquid which is mixable with acetonebut in which nitrocellulose is not soluble.

EMILE BINDSCHEDLER.

GEORGE JUER.

